Gas turbine combustion chamber with telescoping casing and liner sections



DOU GH ERTY June 5, 1956 F, G, 2,748,567

GAS TUREINE coMBUsToN CHAMBERS WITH TELEscoPING CASING AND LINEESECTIONS 2 Sheets-Sheet l Filed Oct. l5, 1949 s@ NNN, .T \e\ .Q KANN. ff mzknk ok 954000, mlv l, l xm@ W nu MN' k n .l N\ ammmmm mm N i@ www TNi@ M E 1 uw w1 Q f NQ \N\\\ \\..\.n mwN, E EN w "1T E n@ EN. NNN

Bnwcntor FLOYD G. DOUGHERTY June 5, 1956 F. G. DOUGHERTY 2,748,567

GAS TUEEINE coMEUsTloN cHAp/.EEES WITH TEEESCOPING CASING AND LINEESECTIONS Filed oct. 15, 1949 2 sheets-shewL 2 Snucntor F LOYD G.DOUGHERTY United States Patent O GAS TURBINE COMBUSTION CHAMBER WITH'TELESCOPING CASING AND LINER SECTIONS Floyd G. Dougherty, Indianapolis,Ind., assigner to General Motors Corporation, Detroit, Mich., acorporation of Delaware Application October 13, 1949, Serial No. 121,105

8 Claims. (Cl. 6039.32)

This invention relates to impulse or jet engine construction and moreparticularly to specific combustion chamber or burner constructiontherefor so that the same may be easily serviced and parts replaced. ltis, of course, common knowledge that jet engines operate at extremelyhigh temperatures which reduce the life of various parts to a relativelyshort period. Special alloys and metals for withstanding heat are usedwhenever feasible but even then it frequently becomes necessary toreplace parts which have been deteriorated by the heat beyond furtherutility. One of the regions subjected toA the highest temperatures is,of course, the combustion chamber or burner unit itself, where thecombustion of the fuel takes place, and it is particularly with theburner construction that the present invention deals.

Jet engines are commonly built with a number of burner units mounted incircular relation around a central shaft upon which is mounted a turbineat one end to drive the shaft and an impeller on the opposite end tocompress the air for the burners. Each one of the burners is a completecombustion unit in itself, which feeds a common output chamber for theengine. Into the burner there are introduced a flow of fuel and at thesame time a suicient amount of air to properly burn the fuel introduced.Inasmuch as this is one of the points in the jet engine at whichextremely high temperatures are developed, the burner is apt todeteriorate rapidly, due to said intense heat. In order to providelongerlife for the burner units, liners have been mounted within theburner inside which the actual combustion takes place, and the liners,therefore, are subjected to the maximum heat, and after a period ofoperation can be replaced. The extreme temperatures to which the burnersare subjected, however, cause rapid corrosion and warpage of the partswhich in turn cause ditiiculty in removal and rebuilding.

It is, therefore, an object of my invention to provide lining means fora burner which may be simply and easily installed and removed.

It is a further object of my invention to provide lining means for aburner which is sectional and can be tele- 2,748,567 Patented June 5,1956 Figure 4 is a sectional view taken on line 4 4 of Figure l in thedirection of the arrows.I

Figure 5 shows a sectional View of two sections of the liner intelescoped relation.

Figure 6 is a vertical section through the rear portion of the partiallydisassembled burner showing in dotted lines the movement of the rearsection for removal.

Figure 7 is a sectional view taken on line 7-7 of Figure 6 in thedirection of the arrows.

Referring now more specifically to Figure 1, there isI shown therein onecomplete burner unit identified generally at 2 which, as mentionedbefore, is only one of a plurality of units mounted around a centralshaft to form a complete jet engine. The burner per se is formed ofacentral outer shell 4 having a telescopic similar circu lar member 6which fits within the left-hand end and cart move with respect to themain outer cylinder 4 for purposes of taking up the expansion andcontraction of the-y unit due to heat changes. A bellows element 8 ismounted outside both units and in juxtaposition to the cylinder 6 andhas one end connected at 10 to the mounting means for the cylinder 6 andthe other end rigidly connected as at 12 to the left-hand end of thecylindrical housing 4. Thus, as the temperature is raised and lowered,the two cylindrical parts 4 and 6 may move with respect to each otherbut stillV maintain a substantially closed cylindrical housing.

The mounting means for the cylinder 6 is a ring member 14 which has anotched face surface 16 fitting into a mating notched member 13 carriedby a tapered front assembly 20 rigidly secured to a main frame. When thetwo ring members 14 and 13 are placed in juxtaposition, an outerclamping and restraining band 22 is placed around the assembly andtightly clamped thereto by tightening means not shown. This secures thenose assembly 20 to the main cylindrical housing, The nose section 26also carries a fuel jet 23 which is mounted on the end ofv an inwardlyextending member 24, the latter terminating in a coupling 26 to the fuelline. Mounted inside the nose section is a substantially conical linersection 28, the fuel tube 24 extending through an opening 30 in saidliner 2S to reach the center of the enclosure. A bafe 32' is mounted inthe outer end of the section 28 to divert the incoming air.

Within the main body of the burner is a cylindrical liner 34 which islconnected to and is supported by the inner end of the section 2S, saidconnection being through a plurality of peripherally spaced cap screws35. Section 34 extends'approximately half way back through the maincombustion chamber and terminates within a second cylin-V drical liningshield 36, the two being of different diamscoped together to assist inthe removal of the same from f the burner.

With these and other objects in view which will become apparent as thespecication proceeds, my invention will be best understood by referenceto the following specification and claims and the illustrations in theaccompanying drawings, in which:

Figure 1 is a vertical longitudinal sectional view taken through aburner of my invention.

Figure 2 is an enlarged vertical sectional view showing a portion of theforward section of the burner including the expansion adjustment meansfor the engine and the burner.

Figure 3 is a sectional view taken on line 3--3 of Figure 1, in thedirection of the arrows.

etersV andrcapable of assuming a telescopic relation, the

liner' 34 being of less diameter than liner 36. On the outerv surface atthe left end of the liner 36 as `shownin Figures; 1 and 3 there arelocated Vspaced series of loop members.; 38 which are secured tofsaidouter surface of the member- 36 and extend out to engage the innersurface of the combustionV chamber 4. rThese members act as spacerstolocate the liner properly with respect to the member 4- and also toprovide engageable means for the securing threaded means 40. Threadedmembers 40 are screw` a supporting ring 52 (similar to ring 14 at thefront) which mates with a second supporting ring 54, the latter beingcarried directly by a transition cover plate 55 of irregular shapehaving a central hanged opening 59 therein in which said ring 54 issecured. There are a plurality of these transition plates which aresecured to an annular spider frame 83 by bolts 57, said spider framehaving a circular outside periphery in which a number of spaced teeth 81are provided. Its inner periphery also is provided with a series ofspaced teeth 82. The teeth S1 on the outer periphery engage splines 84carried by the frame 56, and the inner periphery teeth 82 engage in likemanner splines 86, also secured to a portion of the frame. This providesfor longitudinal relative motion between the spider member and the mainframe for accommodating thermal expansion and contraction of the engineand burner assemblies. Gaskets 55a are provided between the transitioncover plates 55 and the spider frame 83. The two mating rings 52 and 54are maintained in juxtaposition in exactly the same manner as the frontpair through an outer ring clamp 58, which is pulled tightly around thesame when assembled. The rear outer section 60 of the burner is securedto frame 83 by welding and is tapered upwardly on one surface 62, butthe upper surface projects substantially horizontally to the rear toform an inside pocket 64 at the top, the purpose of which will later bedescribed. This member terminates in a housing 66 directly connected tothe end of burner section 60, which housing is a part of an annularchamber 68 into which all of the burners discharge. The rear section ofthe liner member is formed of a hollow tapered section 70, the forwardend of which is circular and flared outwardly as at 72 to accommodatethe rear portion of section 36 and which is mounted and spaced from thecasing by loops 71. Section 70 then becomes of smaller dimension on onediameter and greater on the other as it proceeds to the rear until itbecomes of what might be termed a slightly arced rectangular section asat 74 to extend within the member 66 and then slightly outwardly as at80 to form a joint with the outer surface of a collar 76. At this pointthe section 70 is not only of reduced vertical section but is ofconsiderable expanded horizontal section, the general outline being bestshown in Figure 7, where the forward portion appears as a circle whichtapers back to an arcuate section at the rear. This rear arcuatesection, therefore, forms one portion of a complete annular dischargemember, each of the burners providing a similar section and, acting asan assembly, form a complete burner discharge.

Air for the burner, therefore, enters at the front or lefthand portionof Figure l, some of which passes past the bale 32 into the nose section28 sweeping around the fuel jet 23 to cause combustion of the fuel beingfed in that section within sections 34 and 36. Additional air alsopasses through that area outside the nose section 28, but inside thehousing sweeping along the outer surface of the liner 34 to cool thesame and to prevent heat from radiating to the outer housing member 4and then into any one of the series of openings 50 to join with thegases being burned within the chamber, and lastly discharged into therear arcuate opening provided in member 76. Some of the air which sweepsalong the outer surface of the liner 34 also enters the forward portionof the liner 36 inasmuch as the two are designed in telescopic relationand, therefore, the larger rear section 36 will have some air introducedat its forward end. It will be seen, therefore, that the air insulationbetween the liner and the housing 4 will help to prevent the outerhousing from becoming too heated, and also will provide the proper airfor combustion at a distance from the fuel injection.

If it is desired to remove and replace the lining sections after acertain predetermined operation, collar 22 is rst removed, which permitsmovement of cylindrical member 6 by physically pushing it to the rightas shown in Fig. 2 and collapsing the bellows 8. This gives access tobolts and they may be removed around the periphery. The

juncture between the lining sections and the main burner casing is nowcompletely open at this point. Liner 34 is now forced to the right topartially telescope within section 36, as shown in Figure 5. Due to bothcylindrical member 6 and liner 34 being moved to the right space is nowprovided to move the assembly as soon as the right end is disconnected.Collar 58 is then removed thus allowing the burner assembly 2 to bephysically shifted to the left until liner 36 is disengaged with liner70. This permits the burner assembly to be removed on a radial lineoutward from the engine center line. Bolts 57 are now accessible and maybe removed, which permits removal of the transition cover plates 55. Therearmost liner section 70 may then be pulled forward to free its innerend from the member 76 and tilted up as shown in the dash and dot linesof Fig. 6 after which it may be removed with ease. This will permit thereplacement of the liner or other parts of the burner structure asdesired without sacrificing the engine structural strength or requiringmajor engine disassembly. The assembly is conducted in exactly thereverse order to the disassembly.

l claim:

l. A gas turbine combustion apparatus comprising, in combination, outerand inner shells, each shell comprising lixed entrance and exit portionsand a removable intermediate portion connecting the entrance and exitportions of the same shell, the inner shell being contained in the outershell and the two intermediate portions terminating approximately in thesame planes, each intermediate portion comprising two relativelyslidable parts adapted to be telescoped together to shorten theintermediate portions for removal from the entrance and exit portions.

2. A gas turbine combustion apparatus comprising, in combination, outerand inner shells, each shell comprising fixed entrance and exit portionsand a removable intermediate portion connecting the entrance and exitportions of the same shell, the inner shell being contained in the outershell and the two intermediate portions terminating approximately in thesame planes, each intermediate portion comprising two relativelyslidable parts adapted to be telescoped together to shorten theintermediate portions for removal from the entrance and exit portions,and means within the outer shell exposed by telescoping the outer shellfor securing one part of the intermediate portion of the inner shell toone ofthe other portions thereof.

3. A gas turbine combustion chamber comprising, in combination, an outercasing adapted for mounting at each end thereof on fixed mounts in anengine, the outer casing comprising two parts relatively slidable sothat they may be telescoped together for removal from the mounts; aliner adapted for mounting at each end thereof on fixed supports in anengine and disposed within the outer casing, the liner comprising twoparts relatively slidable so that they may be telescoped together forremoval from the supports; and means for securing one of the liner partsto one of the supports located within the casing at a region madeaccessible by telescoping the casing while in place.

4. A gas turbine engine comprising, in combination, an outer combustioncasing adapted for mounting at each end thereof on xed mounts in anengine, the outer casing comprising two parts relatively slidable sothat they may be telescoped for removal from the mounts, a combustionliner adapted for mounting at each end there of on xed supports in anengine and disposed within the outer casing, the liner comprising twoparts relatively slidable so that they may be telescoped for removalfrom the supports, a turbine nozzle, a transition casing connecting oneend of the outer casing to the nozzle, a transition liner for conductingcombustion products to the nozzle connecting the corresponding end ofthe liner to the nozzle and flaring circumferentially of the nozzle, thetransition casing being bulged outwardly to provide for lateraldisplacement of the transition liner at right angles to the direction offlow therethrough for removal thereof.

5. A gas turbine engine comprising, in combination, a turbine nozzle, acombustion chamber, a support spaced from the nozzle and extendingrtransversely of the chamber for supporting the combustion chamber, thesupport including diverging members extending beside the chamber, and atransition combustion section extending from the support to the nozzlefor conducting combustion products to the nozzle, the transition sectioncomprising outer and inner shells, the inner shell widening in thedirection from the support to the nozzle, and the outer transition shellbeing bulged outwardly from the inner shell to permit displacement ofthe inner shell laterally with respect to the support in the directionof divergence of the members during removal or assembly thereof to clearthe radially extending members of the support.

6. A gas turbine engine comprising, in combination, an annular turbinenozzle, a plurality of combustion chambers, a spider spaced from thenozzle for supporting the combustion chambers including membersextending radially of the nozzle between the chambers, and a transitioncombustion section extending from the spider to the nozzle forconducting combustion products to the nozzle, the transition sectioncomprising an outer shell and a plurality of inner shells, the innershells diverging circumferentially of the nozzle from the spider to thenozzle, and the radially outer surface of the outer transition shellbeing bulged outwardly from the inner shells to permit radially outwarddisplacement of the inner shells relative to the axis of the nozzleduring removal or assembly thereof to clear the radially extendingmembers of the spider.

7. A gas turbine combustion apparatus comprising, in combination, outerand inner shells, each shell comprising fixed entrance and exit portionsand an intermediate portion connecting the entrance and exit portions ofthe same shell, the intermediate portions being longer than the distancebetween the entrance and exit portions of the outer shell, the innershell being contained in the outer shell, each intermediate portioncomprising two relatively slidable parts capable of being telescopedtogether to shorten the intermediate portions to a length less than saiddistance for removal from the entrance and exit portions.

8. A gas turbine combustion chamber comprising, in combination, outerand inner shells, the outer shell comprising fixed entrance and exitsections and a removable intermediate section connecting the entranceand exit sections, the inner shell being mounted within the outer shelland comprising an upstream portion and a downstream portion bothsupported from the outer shell and an intermediate portion connectingand supported by the upstream and downstream portions, the intermediateportion being connected to the outer shell only through the upstream anddownstream portions, the intermediate portion being slidably connectedto the other portions of the inner shell, and readily detachable meanssecuring the intermediate portion to one of other portions and locatingthe intermediate portion with respect to the said other portion.

References Cited in the tile of this patent UNITED STATES PATENTS2,268,464 Seippel Dec. 30, 1941 2,337,038 Fentress Dec. 21, 19432,432,359 Streid Dec. 9, 1947 2,445,114 Halford July 13, 1948 2,479,573Howard Aug. 23, 1949 2,493,641 Putz lan. 3, 1950 2,547,619 Buckland Apr.3, 1951 2,548,886 Howard Apr. 17, 1951 2,610,467 Miller Sept. 16, 19522,650,753 Howard et al. Sept. l, 1953 FOREIGN PATENTS 576,545 GreatBritain Apr. 9, 1946 0 tion Week.

